Memorial of the fall of Constantinople to the Ottoman Turks in 1453.
On Tuesday, May 29, 1453, after a siege of nearly two months, the armies of Sultan Mehmet II broke through the walls of Constantinople. The Emperor Constantine XI Palaiologos fell fighting at the gate, and the Great Church of Hagia Sophia was taken.
The Church of Greece keeps the day as a memorial of the Queen of Cities and of those who died in her defense.
Feast day
On the New Calendar, Fall of Constantinople is commemorated on May 29. Churches on the Old (Julian) Calendar keep the feast on June 11 of the civil calendar.
Also commemorated on May 29

Theodosia of Tyre
Holy Woman, Θεοδοσία η Παρθένος
Virgin Martyr Theodosia of Tyre, drowned at Caesarea for her faith.
Alexander of Alexandria
Hierarch, Αλέξανδρος Αλεξανδρείας
Saint Alexander, Patriarch of Alexandria, who first condemned Arius.
Hypomone the Righteous
Holy Woman, Υπομονή
Venerable Hypomone, the Empress Helen Dragas, mother of the last Emperor of Constantinople.
John Nannos of Thessalonica
Martyr, Ιωάννης ο Νάννος
New Martyr John Nannos of Thessalonica, beheaded at Smyrna.
Andreas Argentis
Martyr, Ανδρέας ο Αργέντης
New Martyr Andreas Argentis of Chios, beheaded in Constantinople.